The rate of increase in obesity in the Western world is a major health problem affecting millions of people. Bariatric surgical procedures represent a successful way to achieve significant weight reduction in morbidly obese individuals. Following surgery it is estimated that up to one-third of the patients suffer nutritional deficiencies that cannot be corrected by normal diet alone.
From the literature, it is evident that nutritional deficiencies are common in both pre and post bariatric surgery patients. These deficiencies are specific depending on the type of surgery performed and post-operative deficiencies are further exacerbated. In the US the most common gastric bypass procedure is Roux-en-Y gastric bypass (RYGBP), which reduces the size of the stomach using surgical staples to cause restriction [1]. Then, the stomach is reattached to the jejunum, bypassing the duodenum and causing malabsorption. Two other less often performed types of bariatric surgery are: Tube gastrectomy or gastroplasty (TG) and Bilio-pancreatic diversion (BPD). Outside the US, laparoscopic gastric banding (LAGB) is the preferred type of bariatric surgery. In this procedure, a hollow band of special material is placed around the stomach near its upper end, creating a small pouch and a narrow passage into the larger remainder of the stomach.
TG and LAGB are purely restrictive, resulting in a 30-50 ml gastric pouch. Normal absorption is still possible, but deficiencies occur as a result of the greatly reduced overall volume of food intake. RYGBP is predominantly restrictive but also results in mild fat and protein malabsorption. The BPD is a primarily malabsorptive procedure with some restrictions [2,3]. Post surgery patients only are able to eat small portions at the time. To avoid shortages it is therefore crucial that the food offered to them is highly concentrated.
Large liver size impedes laparoscopic surgery in this patient group. An intense pre-surgery weight loss programme (4-6 weeks) has been found to significantly reduce liver size. Currently available weight loss products are not designed to address specific micronutrient needs of this patient group without additional multivitamin supplementation as they only contain micronutrients up to RDA levels. To meet RDAs for micronutrients, up to 5 servings of a protein containing weight management formula may need to be consumed in addition to multivitamins taken several times a day. The need to take several supplements each day can lead to reduced compliance over time resulting in clinical deficiencies.
Protein malnutrition is a real risk in bariatric surgery patients. Many patients require protein supplementation during the early phases of rapid weight loss, to prevent excessive loss of muscle mass. The advantage of a high protein, low calorie product specifically designed to meet or exceed micro-nutrient requirements, for use in patients pre and post bariatric surgery, is that patients can learn to combine healthy eating and product use without total reliance on meal replacers even before the surgical procedure is performed.